Math Fun Library

Question :
What are Unnatural Numbers ?

Answer :
There is no such term called unnatural numbers, but there is a term called negative numbers.
The introduction of negative numbers is due to the need for subtraction to be performable without restriction. In the case of positive numbers the subtraction a - b = c can only be carried out if a is greater than b. If, on the other hand, a is smaller than b we define c = -(b - a).
For example, 7 - 9 = (-2). Here the '-sign' on the left hand side of the equation represents an operation, and on the right hand side it forms part of the number itself.
In the case of the positive numbers the associated sign + may be omitted, but such is not the case with negative numbers.